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Genetic Analyses Of Striped Bass In The Chesapeake Bay: An Investigation Of Connectivity Among Virginia Subestuaries And An Evaluation Of Close-Kinship Mark Recapture Methodology To Estimate Spawning Abundance., Savannah Michaelsen Jan 2018

Genetic Analyses Of Striped Bass In The Chesapeake Bay: An Investigation Of Connectivity Among Virginia Subestuaries And An Evaluation Of Close-Kinship Mark Recapture Methodology To Estimate Spawning Abundance., Savannah Michaelsen

Dissertations, Theses, and Masters Projects

The striped bass (Morone saxatilis) is an anadromous fish distributed along the eastern coast of North America that currently supports one of the most lucrative and important commercial and recreational fisheries in the region. Since the recovery of the Atlantic stock after a collapse in the late 1970s, studies have focused on understanding the connectivity of major spawning grounds and improving methods of abundance estimation. Studies support strong site fidelity of striped bass to major estuaries along the Atlantic coast, but there has been disagreement about connectivity within the largest spawning ground, the Chesapeake Bay. Additionally, no estimates exist for ...


An Investigation Of Hermaphroditism In R Sp Sb 347, Maureen Catherine Farrell Jan 2015

An Investigation Of Hermaphroditism In R Sp Sb 347, Maureen Catherine Farrell

Dissertations, Theses, and Masters Projects

No abstract provided.


Improvements In Triploid Crassostrea Virginica Production: Characterizing The Diploid Parent, Brian R. Callam Jan 2013

Improvements In Triploid Crassostrea Virginica Production: Characterizing The Diploid Parent, Brian R. Callam

Dissertations, Theses, and Masters Projects

The effect of triploidy to effect faster growth and increased survival compared to diploid oysters is called the ‘triploid advantage’ and this advantage in the Chesapeake Bay for Crassostrea virginica is the principal reason for the value of triploid C. virginica in the Chesapeake Bay, USA. The triploid advantage is hypothesized to be the result of genetic effects, physiological changes, or a combination of both. The causative genetic mechanisms at play may include additive genetic effects and heterosis while the physiological changes obtain from triploid sterility. The triploid advantage was examined by comparing 13 diploid and 13 triploid crosses across ...


Patterns Of Population Structure And Historical Dispersal In Squaloid Sharks: A Species-Level Approach Using Molecular Markers, Ana Christina Pimenta Verissimo Jan 2012

Patterns Of Population Structure And Historical Dispersal In Squaloid Sharks: A Species-Level Approach Using Molecular Markers, Ana Christina Pimenta Verissimo

Dissertations, Theses, and Masters Projects

Squaloids (Order Squaliformes) are a highle diverse group of mostly deepwater habitats (> 200 m). Many species are regularly caught in commercial fisheries worldwide but their low productivity and correspondingly low intrinsic rebound potentials make them particularly vulnerable to population depletion and overexploitation. of special concern to fisheries management and conservation efforts are the spiny dogfish Squalus acanthias, the leafscale gulper shark Centrophorus squamosus and the Portuguese dogfish Centroscymnus coelolepis. These taxa have recently been declared overfished in several parts of each species' distribution but management efforts have been made to recover the "stocks" without a good understanding of the species ...


Physiological And Morphological Characterization Of Genetically Defined Classes Of Interneurons In Respiratory Rhythm And Pattern Generation In Neonatal Mice, Maria Cristina De Guzman Picardo Jan 2012

Physiological And Morphological Characterization Of Genetically Defined Classes Of Interneurons In Respiratory Rhythm And Pattern Generation In Neonatal Mice, Maria Cristina De Guzman Picardo

Dissertations, Theses, and Masters Projects

Breathing in mammals depends on an inspiratory-related rhythm that is generated by glutamatergic neurons in the preBotzinger complex (preBotC), a specialized site of the lower brainstem. Rhythm-generating preBotC neurons are derived from a single lineage that expresses the transcription factor (TF) Dbx1, but the cellular mechanisms of rhythmogenesis remain incompletely understood. to elucidate these mechanisms we comparatively analyzed Dbx1-expressing neurons (Dbx1 +) and Dbxl- neurons in the preBotC in knock-in transgenic mice. Whole-cell recordings in rhythmically active newborn mouse slice preparations showed that Dbx1 + neurons activate earlier in the respiratory cycle and discharge greater magnitude inspiratory bursts compared to Dbxl - neurons ...


Molecular Genetic Studies Of Hematodinium Sp., A Parasitic Dinoflagellate Of The Blue Crab, Callinectes Sapidus, Katrina M. Pagenkopp Lohan Jan 2011

Molecular Genetic Studies Of Hematodinium Sp., A Parasitic Dinoflagellate Of The Blue Crab, Callinectes Sapidus, Katrina M. Pagenkopp Lohan

Dissertations, Theses, and Masters Projects

Economically viable fisheries for the American blue crab, Callinectes sapidus, occur in the USA from Delaware Bay to the Gulf of Mexico. Unfortunately, a number of factors, including overexploitation, degraded habitats, and disease, have contributed to the decline of blue crab populations in the USA. In April 2008, the Secretary of Commerce declared the blue crab fishery in the Chesapeake Bay a "commercial fishery disaster." One factor potentially contributing to the decline of blue crab populations in high salinity waters is infection with Hematodinium sp., a parasitic dinoflagellate, which can cause significant mortalities in blue crab populations. Since the first ...


Genetic Diversity Of The Pathogen Streptococcus Parauberis Isolated From Bovine And Piscine Hosts, Stephen Douglas Cole Jan 2011

Genetic Diversity Of The Pathogen Streptococcus Parauberis Isolated From Bovine And Piscine Hosts, Stephen Douglas Cole

Dissertations, Theses, and Masters Projects

No abstract provided.


Searching For The Seed Plant Ethylene Pathway In A Basal Plant Lineage: A Genomic Approach, Ashley R. Decarme Jan 2011

Searching For The Seed Plant Ethylene Pathway In A Basal Plant Lineage: A Genomic Approach, Ashley R. Decarme

Dissertations, Theses, and Masters Projects

No abstract provided.


Female Plumage Coloration In Eastern Bluebirds, Sialia Sialis: Is It A Sexually Selected Trait?, Joanna Kay Hubbard Jan 2009

Female Plumage Coloration In Eastern Bluebirds, Sialia Sialis: Is It A Sexually Selected Trait?, Joanna Kay Hubbard

Dissertations, Theses, and Masters Projects

No abstract provided.


Understanding The Reproductive Behavior And Population Condition Of The Sandbar Shark (Carcharhinus Plumbeus) In The Western North Atlantic: A Molecular Approach To Conservation And Management, David S. Portnoy Jan 2008

Understanding The Reproductive Behavior And Population Condition Of The Sandbar Shark (Carcharhinus Plumbeus) In The Western North Atlantic: A Molecular Approach To Conservation And Management, David S. Portnoy

Dissertations, Theses, and Masters Projects

The sandbar shark, Carcharhinus plumbeus, has a discontinuous cosmopolitan distribution and is exploited throughout much of its range. In the western North Atlantic, it constitutes the majority of the directed commercial fishery. The stock has declined greatly since the fisheries' inception and has not shown signs of recovery despite the implementation of management practices. Like many highly vagile marine species, it is difficult to obtain information about the sandbar shark through direct observation. Therefore, the goal of this dissertation is to use a molecular approach to examine aspects of behavior and reproduction, providing information useful in conservation and management. to ...


Characterization Of Exotic Pathogens Associated With The Suminoe Oyster, Crassostrea Ariakensis, Jessica A. Moss Jan 2007

Characterization Of Exotic Pathogens Associated With The Suminoe Oyster, Crassostrea Ariakensis, Jessica A. Moss

Dissertations, Theses, and Masters Projects

The eastern oyster, Crassostrea virginica, once an integral part of the ecology and economy of Chesapeake Bay, has been severely depleted. Factors leading to the decline of the eastern oyster include over-harvesting, environmental degradation and disease pressure caused by the protozoans Haplosporidium nelsoni and Perkinsus marinus, known commonly as MSX and Dermo, respectively. Studies regarding the feasibility of introducing a nonnative oyster to the Bay were initiated, and field-based research on an Asian oyster, Crassostrea ariakensis, suggested that it might be a viable species for introduction. Research surrounding the proposed introduction has focused on recommendations such as those from the ...


Monograph Of The North American Freshwater Fish Leeches (Oligochaeta: Hirudinida ; Piscicolidae) And Molecular Phylogeny Of The Family Piscicolidae, Julianne I. Williams Jan 2007

Monograph Of The North American Freshwater Fish Leeches (Oligochaeta: Hirudinida ; Piscicolidae) And Molecular Phylogeny Of The Family Piscicolidae, Julianne I. Williams

Dissertations, Theses, and Masters Projects

The phylogeny of the Piscicolidae was analyzed from combined sequence data of 18S rDNA, cytochrome c oxidase subunit I (CO-I), nicotinamide adenine dinucleotide dehydrogenase subunit I (ND-I), and morphological data using parsimony. A worldwide distribution of Pisciolidae was represented for the first time in a phylogenetic analysis. While the family Piscicolidae was supported as a monophyletic group, the traditional subfamilies based on morphology were not supported. The Platybdellinae was polyphyletic and formed four distinct clades, and Bathybdella sawyeri did not group with any other platybdellids. The Piscicolinae was also polyphyletic, also forming four distinct clades. The pontobdellid genus Stibarobdella was ...


Population Genetic Structure Of Escolar (Lepidocybium Flavobrunneum) And A Molecular Phylogeny Of The Trichiuroidea, Kirsten Brendtro Jan 2006

Population Genetic Structure Of Escolar (Lepidocybium Flavobrunneum) And A Molecular Phylogeny Of The Trichiuroidea, Kirsten Brendtro

Dissertations, Theses, and Masters Projects

No abstract provided.


A Genetic Analysis Of The Intraspecific Relationships Of Tropical Marine Shorefishes Common To Bermuda And The Southeastern Atlantic Coast Of The United States, Kelly R. Johnson Jan 2003

A Genetic Analysis Of The Intraspecific Relationships Of Tropical Marine Shorefishes Common To Bermuda And The Southeastern Atlantic Coast Of The United States, Kelly R. Johnson

Dissertations, Theses, and Masters Projects

No abstract provided.


A Genetic Investigation Of Population Structure And Phylogenetics Of The Benthic Polychaete Paraprionospio Pinnata In Chesapeake Bay, Julie Beck Stubbs Jan 2003

A Genetic Investigation Of Population Structure And Phylogenetics Of The Benthic Polychaete Paraprionospio Pinnata In Chesapeake Bay, Julie Beck Stubbs

Dissertations, Theses, and Masters Projects

No abstract provided.


Genetic Variation Within And Among The Suminoe Oyster (Crassostrea Ariakensis) Populations And Stocks As Assessed By Molecular Markers, Qian Zhang Jan 2003

Genetic Variation Within And Among The Suminoe Oyster (Crassostrea Ariakensis) Populations And Stocks As Assessed By Molecular Markers, Qian Zhang

Dissertations, Theses, and Masters Projects

No abstract provided.


Genetic Stock Structure Of The Sailfish, Istiophorus Platypterus, Based On Nuclear And Mitochondrial Dna, Jan Renee Mcdowell Jan 2002

Genetic Stock Structure Of The Sailfish, Istiophorus Platypterus, Based On Nuclear And Mitochondrial Dna, Jan Renee Mcdowell

Dissertations, Theses, and Masters Projects

The results of life history studies involving the sailfish, Istiophorus platypterus, from the Atlantic, Pacific, and Indian oceans were reviewed. Results of studies agree on several aspects of sailfish biology; sailfish exhibit opportunistic feeding behavior, follow the 28??C isotherm, spawn in summer mature at approximately age 3, and are the least migratory of the billfishes. However, results are in conflict concerning sex ratio and whether sailfish are single or multiple spawners. Although many researchers have reported that sailfish are sexually dimorphic, their fragile otoliths make them difficult to age, aging studies have not been validated, and sexual dimorphism has ...


Molecular And Morphological Evolution Of The Amphipod Radiation Of Lake Baikal, Kenneth S. Macdonald Iii Jan 2002

Molecular And Morphological Evolution Of The Amphipod Radiation Of Lake Baikal, Kenneth S. Macdonald Iii

Dissertations, Theses, and Masters Projects

The amphipods of Lake Baikal, Russia, are a taxonomically and morphologically diverse group, and have been cited as a classic example of adaptive radiation. An unfortunate consequence of this diversity has been an instability of Baikal amphipod classification, with frequent revisions spurred by differing opinions about the phylogenetic utility of different characters. Classifications have never been based on a rigorous phylogenetic analysis of morphological data and only recently has the phylogeny of Lake Baikal's amphipods been examined using molecular tools. Unfortunately, most of these studies have led to a limited expansion of our understanding of Baikal amphipod systematics. Phylogenetic ...


Genetic Investigation Of Interspecific And Intraspecific Relationships Within The Genus Rapana, Arminda L. Gensler Jan 2001

Genetic Investigation Of Interspecific And Intraspecific Relationships Within The Genus Rapana, Arminda L. Gensler

Dissertations, Theses, and Masters Projects

No abstract provided.


Application Of Genetic Markers To Provide Species Identification And Define Stock Structure: Analyses Of Selected Marine Fishes Of The Mid -Atlantic Bight, Jan F. Cordes Jan 2000

Application Of Genetic Markers To Provide Species Identification And Define Stock Structure: Analyses Of Selected Marine Fishes Of The Mid -Atlantic Bight, Jan F. Cordes

Dissertations, Theses, and Masters Projects

Molecular markers and techniques were employed to develop a genetic key for the forensic identification of 16 species of Chesapeake Bay sportfishes and to investigate the stock structure of one of those species, the weakfish Cynoscion regalis. Regions within the ATP synthetase 6 (ATPase 6), Cytochrome b , cytochrome c oxidase I, NADH dehydrogenase 4 (ND4), and 12S/16S ribosomal RNA mitochondrial genes were amplified using the polymerase chain reaction (PCR) and digested with a bank of restriction endonucleases to find a genetic marker that exhibited complete interspecific differentiation and low intraspecific variation. Complete separation of all sixteen species was accomplished ...


A Molecular Phylogeny Of The Sparidae (Perciformes: Percoidei), Thomas M. Orrell Jan 2000

A Molecular Phylogeny Of The Sparidae (Perciformes: Percoidei), Thomas M. Orrell

Dissertations, Theses, and Masters Projects

The Sparidae are a diverse group of over 110 marine species whose putative six subfamilies have been defined primarily on the basis of dentition and feeding type. Monophyly of the subfamilies has not been tested, nor have the phylogenetic relationships of all sparid genera been hypothesized. I used mitochondrial DNA sequences from the complete cytochrome b gene (1140 bp) and the partial 16S gene (621 bp) in independent and combined analyses to test the monophyly of the Sparidae, elucidate the inter-relationships of the 33 recognized genera of the Sparidae, test the validity of the six subfamilies of the Sparidae, and ...


Biogeography Of Amphi-Atlantic And Amphi-American Fishes: The Scomberomorus Regalis (Scombridae), Strongylura Marina (Belonidae) And Hyporhamphus Unifasciatus (Hemiramphidae) Species Groups, Heidi M. Banford Jan 1998

Biogeography Of Amphi-Atlantic And Amphi-American Fishes: The Scomberomorus Regalis (Scombridae), Strongylura Marina (Belonidae) And Hyporhamphus Unifasciatus (Hemiramphidae) Species Groups, Heidi M. Banford

Dissertations, Theses, and Masters Projects

Phylogenetic and historical biogeographic hypotheses were explored for three groups of teleost fishes that are hypothesized to share a common biogeographic track. Distributed across the eastern Pacific/eastern Atlantic (EP/EA) biogeographic track of Rosen (1975) are the Scomberomorus regalis (Scombridae), Strongylura marina (Belonidae) and Hyporhamphus unifasciatus (Hemiramphidae) species groups comprised of one eastern Atlantic; three, three and four western Atlantic; and two, two and four eastern Pacific species, respectively, for each group. In addition, two species in the Strongylura marina and Hyporhamphus unifasciatus groups, have invaded freshwater drainages of Central and South America. Each of the three species groups ...


The Phylogeny Of Coleoid Cephalopods Inferred From Molecular Evolutionary Analyses Of The Cytochrome C Oxidase I, Muscle Actin, And Cytoplasmic Actin Genes, David Bruno Carlini Jan 1998

The Phylogeny Of Coleoid Cephalopods Inferred From Molecular Evolutionary Analyses Of The Cytochrome C Oxidase I, Muscle Actin, And Cytoplasmic Actin Genes, David Bruno Carlini

Dissertations, Theses, and Masters Projects

Although the fossil record of early cephalopods is rich and demonstrates the dominance of the group in Paleozoic times, the mainly soft-bodied coleoids (Cephalopoda: Coleoidea) are poorly represented. Therefore, little is known of the evolutionary history of coleoids through paleontology and current classifications of the subclass are based primarily on the morphology of extant representatives. A molecular phylogenetic analysis of the Coleoidea was therefore warranted. Phylogenetic relationships within the Coleoidea were constructed using molecular sequence data from one mitochondrial and two nuclear genes: cytochrome c oxidase I (COI) and two unlinked actin genes (Actin I and Actin II, respectively). A ...


Comparative Evolution Of Molecular Markers: An Analysis Of Genetic Variation Within The Blue Marlin (Makaira Nigricans), Vincent Patrick Buonaccorsi Jan 1998

Comparative Evolution Of Molecular Markers: An Analysis Of Genetic Variation Within The Blue Marlin (Makaira Nigricans), Vincent Patrick Buonaccorsi

Dissertations, Theses, and Masters Projects

Blue marlin diversity was assessed at mtDNA, scnDNA, microsatellite DNA, and allozyme molecular markers. Hierarchical analysis of molecular variance (AMOVA) revealed that most genetic variation was maintained within populations, with a non-significant fraction attributable to variation among temporal replicates and between locations within oceans. In contrast, inter-ocean divergence was highly significant for a majority of loci within each marker class. Previous studies of mitochondrial DNA (mtDNA; n = 104) genetic variation within the blue marlin revealed two distinct clades of haplotypes, one of which was present only in the Atlantic (the 'Atlantic clade'), at a frequency of 40% &(F\sb{lcub ...


Phenotypic Clines In The Intertidal Snail Littorina Obtusata: The Role Of Water Temperature And Predator Effluent As Inducers Of Phenotypic Plasticity And Associated Trade-Offs In Shell Form, Geoffrey Clayton Trussell Jan 1998

Phenotypic Clines In The Intertidal Snail Littorina Obtusata: The Role Of Water Temperature And Predator Effluent As Inducers Of Phenotypic Plasticity And Associated Trade-Offs In Shell Form, Geoffrey Clayton Trussell

Dissertations, Theses, and Masters Projects

I examined variability in the shell form of 25 Littorina obtusata populations from Massachusetts to northern Maine. I chose this scale because the history of one of L. obtusata's principal predators, the crab Carcinus maenas, has changed dramatically in the past 100 years. Before 1900, Carcinus did not occur north of Cape Cod, Massachusetts, but by 1950 it had reached Canadian border. Moreover, in summer water temperatures during average 6-8&\sp\circ&C colder at northern locations. Shell thickness and mass increased and body mass decreased with increasing latitude. to test whether these patterns reflect plasticity in response to ...


Systematic And Population Genetic Analyses Of Northern Vs Southern Yellow Lady's Slippers (Cypripedium Parviflorum Vars Parviflorum, Pubescens, And Makasin): Inference From Isozyme And Morphological Data, Lisa Ellen Wallace Jan 1997

Systematic And Population Genetic Analyses Of Northern Vs Southern Yellow Lady's Slippers (Cypripedium Parviflorum Vars Parviflorum, Pubescens, And Makasin): Inference From Isozyme And Morphological Data, Lisa Ellen Wallace

Dissertations, Theses, and Masters Projects

No abstract provided.


Genetic Relationships Among Geographically Isolated Populations Of Bluefish (Pomatamus Saltatrix), Catherine N. O'Neill Jan 1995

Genetic Relationships Among Geographically Isolated Populations Of Bluefish (Pomatamus Saltatrix), Catherine N. O'Neill

Dissertations, Theses, and Masters Projects

No abstract provided.


Determination Of The Natal Origin And Genetic Stock Composition Of A Juvenile Feeding Population Of The Loggerhead Turtle (Caretta Caretta) In Chesapeake Bay, Jeffrey Worner Norrgard Jan 1995

Determination Of The Natal Origin And Genetic Stock Composition Of A Juvenile Feeding Population Of The Loggerhead Turtle (Caretta Caretta) In Chesapeake Bay, Jeffrey Worner Norrgard

Dissertations, Theses, and Masters Projects

No abstract provided.


A Correlated Lm/Sem Method For The Morphological Characterization Of Gene Expression In Xenopus Laevis, Laura Rochmis Jan 1995

A Correlated Lm/Sem Method For The Morphological Characterization Of Gene Expression In Xenopus Laevis, Laura Rochmis

Dissertations, Theses, and Masters Projects

No abstract provided.


Population Genetics Of Selected Species Of Sharks, Edward J. Heist Jan 1994

Population Genetics Of Selected Species Of Sharks, Edward J. Heist

Dissertations, Theses, and Masters Projects

Molecular genetic techniques were used to elucidate genetic population structure in three species of sharks, the coastal sandbar shark (Carcharhinus plumbeus) and Atlantic sharpnose shark (Rhizoprionodon terraenovae), and the pelagic shortfin mako (Isurus oxyrinchus). Allozyme analysis and analysis of restriction fragment length polymorphisms (RFLP) of mitochondrial DNA (mtDNA) were used to test the null hypothesis that the mid-Atlantic Bight and the Gulf of Mexico sandbar sharks consist of a single gene pool. RFLP analysis of mtDNA was used to determine the pattern and level of genetic divergence in the sandbar shark between the western North Atlantic and the Eastern Indian ...